THE CA.NADIAN ENTOMOLOGIST. 15 



although the authors have neglected to sift out the older species belonging 

 to these new groups. Accordingly, the older genera, like Sargus for 

 example, contain species of several of the modern subdivisions. 



In the following pages are listed the species studied, together with 

 the localities from which they were received. Analytical keys are intro- 

 duced for several of the genera as an aid to the -future student. I here 

 wish to thank ray friend, Mr. Charles T. Brues^ for supplying descriptions 

 not accessible in this city. 



AT.LOr.NOSTA. 



Our three species are related thus : 



Discal cell not as broad as the stigma .2. 



Discal cell as broad as the stigma 5 abdomen testaceous 



centrally  fiiscif arsis. Say. 



2. Abdomen testaceous centrally simi/is, Loew. 



A.bdomen wholly black obsciiriventris, Loew. 



A. fusciiarsis, Say. 



Edgebrook and Algonquin, III.: Kiamesha, N. Y. June. 



A. obsan'iventris, Loew. 



Edgebrook, 111. June. This species occurs in company, wiih the 

 preceding in open woodland. 



Beris. 



But two species occur in the United States. They have the thorax 

 metallic green and the abdomen black. 



Scutellum with four spines viridis, Say. 



Scutellum with six or eight spines Mexicana, Bell, Will. 



B. viridis, Say. 



New Jersey (vi., 3, '01) ; Michigan ; Glen EUyn, 111. (v., 30, '99). 



B. Mexicana, Bellardi, Williston. 



One specimen from Vancouver Island (Livingston, vii., 14, '96) 

 agrees with Dr. Williston's redescription of this species (Can. Ent., 1885, 



P- 123). 



Sargus. 

 The species grouped under the old genus Sargus are many of them 

 superficially described. Accordingly, it would be difficult to decide to 

 which subdivision most of the species belong. So far the species 

 described under the generic name Sargus may be distributed among the 

 following grou]')S ; 



